Back to EveryPatent.com
United States Patent | 6,240,271 |
Shimazawa ,   et al. | May 29, 2001 |
Developing devices are provided adjacent to a light sensitive element. An intermediate transfer drum is provided adjacent to the light sensitive elements. After exposure of the light sensitive element, a first color or third color image is formed on the light sensitive element. On the other hand, after exposure of the light sensitive element, a second color or fourth color image can be formed on the light sensitive element. The first color image is transferred from the transfer unit to the intermediate transfer drum at the first transfer portion, and the second color image is transferred from the transfer unit at the second transfer portion so as to be superimposed on the first color image. Similarly, the third color image is transferred so as to be superimposed on the second image and the fourth color image is transferred so as to be superimposed on the third color image to the intermediate transfer drum. Accordingly, the first to fourth color images are superimposed. Thereby, downsizing of the device and cost reduction are achieved and image formation speed is facilitated.
Inventors: | Shimazawa; Yoichi (Nara, JP); Matsuda; Hideo (Nara, JP); Maeda; Yasutaka (Kyoto, JP); Anzai; Shunju (Nara, JP); Fujimoto; Osamu (Yamatokoriyama, JP); Sakagami; Hidekazu (Sakurai, JP); Irie; Kazumi (Yamatokoriyama, JP) |
Assignee: | Sharp Kabushiki Kaisha (Osaka, JP) |
Appl. No.: | 238150 |
Filed: | January 28, 1999 |
May 15, 1996[JP] | 8-120612 | |
Mar 11, 1997[JP] | 9-56696 |
Current U.S. Class: | 399/299; 347/115; 399/66; 399/112; 399/223; 399/302 |
Intern'l Class: | G03G 015/01; G03G 015/16 |
Field of Search: | 399/162,112,119,178,179,223,298,299,300,302,303,66 347/115,117,118,119,232 358/1,4 |
3392667 | Jul., 1968 | Cassel et al. | 347/117. |
5121171 | Jun., 1992 | Knapp | 399/299. |
5204729 | Apr., 1993 | Maeda et al. | 399/298. |
5406359 | Apr., 1995 | Fletcher | 399/296. |
5444515 | Aug., 1995 | Haneda et al. | 399/112. |
5550626 | Aug., 1996 | Kobayashi et al. | 399/178. |
5557377 | Sep., 1996 | Lowewen et al. | 399/182. |
5576824 | Nov., 1996 | Folhins et al. | 399/288. |
5613175 | Mar., 1997 | Frankel | 399/162. |
5742887 | Apr., 1998 | Suzuki et al. | 399/302. |
Foreign Patent Documents | |||
0837373 | Apr., 1998 | EP. | |
58-95361 | Jun., 1983 | JP. | |
59-123861 | Jul., 1984 | JP. | |
6-059373 | Apr., 1985 | JP. | |
60-169862 | Sep., 1985 | JP. | |
6-321670 | Jan., 1988 | JP. | |
634250 | Jan., 1988 | JP. | |
4-204871 | Jul., 1992 | JP. | |
4221974 | Aug., 1992 | JP. | |
6143701 | May., 1994 | JP. | |
7-244414 | Sep., 1995 | JP. | |
836346 | Feb., 1996 | JP. | |
8-123123 | May., 1996 | JP. |
TABLE 1 The developing device used The developing device used in the first rotation of the in the second rotation of the intermediate transfer drum intermediate transfer drum 23 23 The first The second The first The second process process process process Mode portion 21 portion 22 portion 21 portion 22 1 26 or 27 32 or 33 Not used Not used 2 26 or 27 Not used 27 or 26 Not used 3 Not used 32 or 33 Not used 33 or 32